Heading into the G-20 summit in Seoul last week, tensions were visibly high between the U.S. and China, the world's top-two economies. Washington's demands that China allow its currency, the yuan, to appreciate were met with criticisms from Beijing about the Fed's inflationary monetary policy. At the heart of the argument lay global current account imbalances, largely a consequence of the sizeable U.S. trade deficit with China. By the close of the summit, the U.S. delegation succeeded in getting the Chinese to acknowledge that these imbalances were problematic for the global economy, but failed in getting them to do anything about it.

In the end, this result says less about the G-20's ability to coordinate policy than it does about the changing distribution of global power: The U.S., long able to influence the domestic economic policies of its major trading partners, now faces interlocutors that are increasingly immune to its suasion.

Current account imbalances weren't the only issue on the agenda at Seoul. Other outcomes included an endorsement of the Basel III global banking regulations, an acknowledgement that emerging-market economies should be able to use capital controls to curb speculative financial inflows, and finalization of plans to rebalance voting power within the IMF. The latter two, on balance, can be seen as a victory for the emerging-market members of the group.

But these issues were secondary to the issue of global imbalances. Leading up to Seoul, the U.S. was lobbying for the G-20 to agree on a plan that would cap current account surpluses and deficits at 4 percent of gross domestic product (GDP). With the U.S. running a current account deficit of around 3 percent and China running a surplus of nearly 5 percent, this was clearly targeted at Beijing.

Washington's inability to persuade Beijing that its plan was necessary is a salient symbol of the changing face of global power, one that becomes even more striking when the Seoul Summit is contrasted with a similar meeting on global imbalances that took place 25 years ago. While the conditions were quite similar, the differences in outcome could not be starker.

The year was 1985. Like today, the U.S. was slowly emerging from the economic doldrums. Like today, it was running a current account deficit of nearly 3 percent, largely due to a significant trade imbalance with a major Asian economy. Like today, exchange rates were at the heart of the imbalances. Like today, protectionist fervor was on the rise in the U.S., threatening the free trade regime.

Of course, Japan was the "culprit" then, not China. The U.S. said that the dollar was overvalued and that the yen -- as well as other major currencies -- was undervalued.

It was in this context that the G-5 nations -- comprised of the U.S., Japan, the U.K., West Germany, and France -- met at the Plaza Hotel in New York to discuss the problem of global imbalances. But the results of what became known as the Plaza Accord were starkly different from the outcome of last week's Seoul Summit. The G-5 emerged from the meeting with a plan that would lead to a number of coordinated interventions by the five central banks in international currency markets. By the time the interventions were finished, the dollar's value had declined by nearly 50 percent, while the yen had appreciated by the same amount.

In 1985, the U.S. got its way. In 2010, the U.S. got a rain check.

It would be easy to paint the outcome of the Seoul Summit as simply the latest exhibit in the circumstantial case proving America's relative decline. However, power can be a very ambiguous term if used loosely, as it often is. The political economist Benjamin Cohen distinguishes between two types of power: power as influence and power as autonomy. Power as influence, which is how we typically conceptualize power, implies the ability of actor A to get actor B to do what B otherwise would not do. On the other hand, as Cohen explains (.pdf), "power [as autonomy] does not mean influencing others; rather, it means not allowing others to influence you."

Cohen's distinction is an important one, and helps to characterize the power shift represented by the Seoul Summit. To say that the balance of economic power is shifting in favor of China might lead some to believe that Beijing is now dictating terms to Washington, which is not the case. The power that China has today -- and the power that Japan did not have in 1985 -- is power as autonomy. What China does not yet have vis-Ã -vis the U.S. is power as influence. Similarly, what the U.S. has lost vis-Ã -vis its economic rivals is power as influence. Yet, it clearly maintains its autonomy as exemplified by the Fed's internationally unpopular "Quantitative Easing 2".

So what happens when all of the world's economic heavyweights have autonomy, but none has influence? With no country able to impose its preferences on the others, consensus becomes increasingly difficult if not impossible on certain issues. As was the case in Seoul, that means you often get a draw -- with all the risks that entails for a globalized economy.

Daniel McDowell is a Ph.D. candidate in International Relations at the University of Virginia, specializing in International Political Economy.